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From: legg <legg@nospam.magma.ca>
Newsgroups: sci.electronics.design
Subject: Re: power supply discharge
Date: Sun, 29 Sep 2024 09:14:42 -0400
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On Sat, 28 Sep 2024 11:56:52 -0700, KevinJ93 <kevin_es@whitedigs.com>
wrote:

>On 9/28/24 6:44 AM, legg wrote:
>> On Fri, 27 Sep 2024 08:07:29 -0700, john larkin <JL@gct.com> wrote:
>> 
>>>
>>> Given a benchtop power supply, you can turn the voltage up and then
>>> down, and it goes down. Most have a substantial amount of output
>>> capacitance, and can be driving an external cap too. So something
>>> pulls the output down.
>>>
>>> I guess that there are no standards for this, but I've never seen a
>>> supply that just hangs high when it's cranked down.
>>>
>>> I'm designing some programmable multi-channel power suplies and that
>>> is one of many tangled issues in the project.
>> 
>> Twiddling the adjustment knob on a bench supply doesn't
>> represent a dramatic change - and most adjustible
>> supplies don't load their output terminals with a
>> lot of capacitance.
>> 
>> DC coupled programable supplies, or bipolar programmable
>> supplies are made to drive loads in the first and third
>> quadrants.
>> 
>> There are issues in the second and fourth quadrants, where
>> the supply is expected to absorb power.
>> 
>> An amplifier driving a pure reactance experiences the same
>> losses as driving a dead short.
>> 
>> RL
>
>Some specialist power supplies for large scale battery testing can 
>absorb power and return it to the AC supply.
>
>https://eepower.com/tech-insights/regenerative-power-supplies-create-lots-of-energy-at-electronica/#
>
>kw

It's always made more sense in power test gear, if 
you can afford it. It's a penny-pinching part of 
the industry.

In the loading case, you don't end up contributing much to 
the line, you just draw net losses from processing, so no 
complications for hydro.

For PV or other energy sources - it's a negotiation that's 
dependent on local supplier and contracted regs.

RL